Novel formulation of phosphorus fertilizer for plants

ABSTRACT

Concentrated phosphorus fertilizers are disclosed that comprise a buffered composition of an organic acid and salts thereof and a phosphorous-containing acid and salts thereof. The concentrated phosphorus fertilizers can be diluted with water of pH ranging from about 6.5 to about 8.5 at ratios of concentrate to water at about 1:40 to about 1:600 to result in a fertilizer having a pH in the range acceptable for foliar uptake of phosphorus.

BACKGROUND OF THE INVENTION

Fertilizers are added to the soil of crops or in some cases they can beapplied directly to crop foliage to supply elements needed for plantnutrition. Seventeen elements are known to be essential to the healthand growth of plants. Typically, nitrogen, phosphorus, and potassium areprovided in the greatest quantity. With increasing knowledge of the roleof each of the nutrients essential to plants, there is a betterunderstanding of the importance of providing a given nutrient at theappropriate stage of phenology. To accomplish this, rapid changes infertilizer formulations and methods of application have been necessary.

Another factor changing fertilization formulations and methods is due topressure from federal, state and local regulatory agencies and citizengroups to reduce the total amount of fertilizer in general, and ofspecific nutrients in particular, being applied to the soil.Additionally, the loss of registration of existing synthetic plantgrowth regulators and organic pesticides and the prohibitively highcosts involved in the successful registration of new ones, also plays arole in the changing arena of crop fertilization.

The principal source of phosphorus for the fertilizer industry isderived from the ores of phosphorus-containing minerals found in theEarth's crust, termed phosphate rock. Elemental phosphorus does notexist in nature; plants utilize phosphorus as the dihydrogen phosphateion (H₂PO₄ ⁻). While untreated phosphate rock has been used forfertilizer, it is most commonly acidulated with dilute solutions ofstrong mineral acids to form phosphoric acid, which is more readilyabsorbed by crops.

Until recently, phosphate and polyphosphate compounds were consideredthe only forms in which phosphorus could be supplied to plants to meetthe plant's nutritional need for phosphorus. Indeed, the only phosphitecompound cited for use as a fertilizer in the Merck Index (M. Windhols,ed., 1983, 10th edition, p. 1678) is calcium phosphite (CaHPO₃). Nophosphite fertilizer formulations are listed in The Farm ChemicalHandbook (Meister Publishing Co., 1993, Willoughby, Ohio 834 p.) orWestern Fertilizer Handbook (The Interstate, Danville, Ill. 288 p.)Historically, calcium phosphite was formed as a putative contaminant inthe synthesis of calcium superphosphate fertilizers [McIntyre et al.,Agron. J. 42:543-549 (1950)] and in one case, was demonstrated to causeinjury to corn [Lucas et al., Agron. J. 71:1063-1065 (1979)].Consequently, phosphite was relegated for use only as a fungicide(Alliete®; U.S. Pat. No. 4,075,324) and as a food preservative.

More recently, it has been shown that plants can obtain phosphorus fromphosphite [Lovatt, C. J., Mar. 22, 1990, “Foliar phosphorusfertilization of citrus by foliar application of phosphite” In: CitrusResearch Advisory Committee (eds) Summary of Citrus Research, Universityof California, Riverside, Calif. pp 25-26; Anon., May, 1990, “Foliarapplications do double duty” In: L. Robison (ed) Citrograph Vol. 75, No.7, p 161; Lovat, C. J., 1990, “A definitive test to determine whetherphosphite fertilization can replace phosphate fertilization to supply Pin the metabolism of ‘Hass’ on ‘Duke 7’:—A preliminary report”California Avocado Society Yearbook 74:61-64; Lovatt, C. J., 1992].Formulations based on phosphorous acid and hypophosphorous acid, asphosphite is, generally undergo oxidation to phosphate and thus lose thebenefits that could be derived from the use of phosphite fertilizationapplications.

The phosphate and polyphosphate fertilizers currently used have a numberof properties that compromise their desirability as fertilizers.Generally, they tend to form precipitates during storage and shipping.This limits the ability to formulate concentrated solutions offertilizers. Additionally, formulations must generally be maintained ata narrow pH range to prevent precipitation, resulting in fertilizersthat are limited to particular uses.

Another drawback of phosphate fertilizers is that they are not readilytaken up by the foliage of many plants and must instead be delivered tothe soil for uptake by plant roots. The mobility of phosphatefertilizers in the soil is limited leading to rapid localized depletionof phosphorus in the rhizosphere and phosphorus deficiency of the plant.Frequent reapplication of phosphate fertilizers is undesirable becauseit leads to leaching of phosphate into the groundwater resulting ineutrophication of lakes, ponds and streams.

Phosphate and polyphosphate fertilizers have also been shown to inhibitthe beneficial symbiosis between the roots of the plants and mycorrhizalfungi. They tend to support the growth of algae and promote bacterialand fungal growth in the rhizosphere, including the growth of pathogenicfungi and other soil-borne pests.

Even though phosphorus, once in the plant, is very phloem mobile (i.e.readily moving from old leaves to young tissues), phosphate is poorlyabsorbed through the leaves of most plant species. This is unfortunatebecause successful foliar phosphorus feeding would result in theapplication of less phosphate fertilizers to the soil and reducephosphorus pollution of the ground water.

Accordingly, there is a need for a phosphorus fertilizer that can beutilized in irrigation systems and applied to foliage without theformation of precipitates that reduce nutrient availability and uptakeby the plant and plug emitters and sprayers. There is also a need fornew methods of fertilizer application that allow nutrients in a readilyavailable form to be supplied at the exact time the plant needs them.This need includes the facility of a foliar product to be sold in asingle formulation for use as a concentrated material for airplane orhelicopter application or as a dilute solution for ground sprayapplication and yet able to be maintained at a suitable pH range optimalfor leaf uptake despite the need to be diluted prior to application.

Additionally, there is a demand for phosphorus fertilizers that have thefacility to be used as liquids or solids (granule or powder). There isalso a demand for fertilizers that do more than just supply nutrients.It is desired that the fertilizers also have demonstrated plant growthregulator activity, increase the plants' resistance to pests, promoteplant health in general and root health in particular, increase theproduction of allelopathic compounds, increase pre- and post-harvestquality, improve stress tolerance, enhance beneficial symbioses, andimprove yield over existing traditional soil or foliar fertilizers.

SUMMARY OF THE INVENTION

Given the above-mentioned deficiencies and demands of fertilizers ingeneral, and of phosphorus fertilizers in particular, it is an object ofthe present invention to provide phosphorus to plants in a formulationthat renders phosphorus readily available to the plants under a numberof application methods such as through soil, foliar uptake, irrigation,and other methods.

It is also an object that the phosphorus fertilizer formulations beconveniently formulated in concentrated solutions that are stable duringstorage and shipping.

Another object of the present invention is to provide a phosphorusfertilizer that is not as inhibitory to mycorrhizal fungi as traditionalphosphate fertilizers.

It is a further object of the present invention to provide a phosphorusfertilizer that does not support the growth of algae to the same degreethat traditional phosphate fertilizers do.

Additional objects and features of the invention will be apparent tothose skilled in the art from the following detailed description andappended claims.

The above objects and features are accomplished by a concentratedphosphorus fertilizer comprising a buffered composition comprising anorganic acid and salts thereof and a phosphorous-containing acid andsalts thereof. The concentrated phosphorus fertilizer can be dilutedwith water of pH ranging from about 6.5 to about 8.5 at ratios ofconcentrate to water at about 1:40 to about 1:600 to result in a fullysolubilized fertilizer having a pH in a range acceptable for foliaruptake of phosphorus.

In one embodiment, the phosphorous-containing acid is selected from thegroup consisting of phosphorous acid, hypophosphorous acid,polyphosphorous acid, and polyhypophosphorous acid and the organic acidis preferably selected from the group consisting of dicarboxylic acidsand tricarboxylic acids such as citrate.

In one embodiment, the concentrated phosphorus fertilizer is anessentially clear liquid devoid of precipitate that can be diluted at aratio of about 1:40 to about 1:600 with water having pH of about 6.5 toabout 8.5, to result in a fertilizer having a pH of about 5.0 to about7.0, and more preferably from about 5.5 to about 6.5, to facilitate theuptake of phosphorus by a variety of plants.

A method of providing phosphorus to plants is also disclosed. The methodcomprises diluting a concentrated phosphorus fertilizer comprising abuffered composition comprising an organic acid and salts thereof and aphosphorous-containing acid and salts thereof with water to form asubstantially fully solubilized use-dilution fertilizer having a pH in arange acceptable for foliar uptake of phosphorus, and applying thefertilizer to the plant foliage.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides phosphorus fertilizers essentially devoidof phosphate. The fertilizer comprises a double or multiple buffersystem of organic acids and their salts with a phosphorous-containingacids and their salts. The formulation stabilizes the phosphorousagainst oxidation to phosphate. Suitable phosphorous-containing acidsare phosphorous acid and polyphosphorous acid, based generally on theformula H₃PO₃, and hypophosphorous acid and polyhypophosphorous acid,based generally on the formula H₃PO₂. Phosphite, the salt of phosphorousacid, has properties that are known to be beneficial to crop production.It is taken up through the foliage of avocado and citrus, two specieswhich classically do not take up phosphate through their foliage.Phosphite has fungicidal properties with regard to some species ofpathogenic fungi: Rhizoctonia solani, Botrytis cinerea, Piriculariaoryzae, Plasmopora viticola, Phytophthora cinnamomi, and Phytophthoraparasitica. Recently, it has been demonstrated that phosphite alsoserves as a source of metabolically active phosphorus in plants. Theproperties of phosphite that make it desirable as a fertilizer areenhanced when it is formulated according to the present invention as adouble or multiple buffer with phosphorous acid, hypophosphorous acid,polyphosphorous acid and/or polyhypophosphorous acid and theirrespective salts and organic acids and their salts per this invention.

Suitable organic acids have the formula R—COOH or R—COO⁻ where R ishydrogen or a carbon-containing molecule or group of molecules. Suitableorganic acids are those that maintain the phosphite ion in asubstantially fully solubilized form upon dilution with water at pHvarying from about 6.5 to about 8.5 and that result in a use dilutionfertilizer having a foliage acceptable pH for phosphorus uptake.Preferred organic acids are dicarboxylic and tricarboxylic acids.

By the term “substantially fully solubilized” it is meant that upondilution, the phosphite does not precipitate, or at least notappreciably, so as to affect administration of the liquid product to theplant foliage, and thus is in a form available to the plant. Withpresent phosphite fertilizers, there is a tendency for phosphite toprecipitate if diluted with alkaline water, thereby rendering thephosphite in a form that is unavailable to the plant for uptake.

By the term “foliage-acceptable pH for phosphorus uptake”, it is meant apH that allows phosphorus to be absorbed by the plant without causingdamage to the foliage. A foliage-acceptable pH for phosphorus uptakeusually ranges between about 5.0 to about 7.0, and preferably betweenabout 5.5 to about 6.5. Phosphorus is most readily taken up by foliageat pH 6.0. Depending on the plant species, a pH below 5.0 can causedamage to leaves and/or the flowers and/or fruit. At higher pH, betweenabout 7.0 to about 7.5, there is reduced uptake of nutrients, althoughgenerally there is no plant damage. A pH between about 7.5 and 8.0,depending on the plant species, plant damage may result. A pH greaterthan 8.0, generally causes damage to the plant in addition to reducinguptake of the nutrients. Accordingly, suitable organic acids are thosethat help provide a “buffered composition” having the desired pH range.This means that a “use-dilution fertilizer” having an acidic to neutralpH (pH 5.0 to 7.0) can be achieved upon high dilutions (up to about{fraction (1/600)}) of the concentrated fertilizer with highly alkalinewater (up to a pH of about 8.5).

Organic acids that meet this criteria include but not limited tointermediates in the Kreb's Tricarboxylic Acid Cycle, amino acids suchas glutamic acid and aspartic acid, vitamin acids such as ascorbic acidand folic acid, and their respective salts. Particularly preferredorganic acids are dicarboxylic and tricarboxylic acids selected from thegroup consisting of citrate, pyruvate, succinate, fumarate, malate,formate, oxaloacetate, citrate, cis-aconitate, isocitrate, andα-ketoglutarate. Citrate is a particularly preferred organic acidbecause of it is relatively inexpensive and readily available.

These formulations allow the maintenance of continued solubility, andthus availability for uptake by plants, of phosphorus, with or withoutother nutrients, over a significantly wide range of concentrations andpHs. The increased solubility of these formulation over that ofphosphate or phosphite fertilizers makes it possible to preparefertilizers with a greater concentration of phosphorus per unit volumethan traditional phosphate or polyphosphate fertilizers or the simpleunbuffered salts of phosphorous acid recently being marketed asfertilizers for foliar application which are available as supersaturated solutions with only about 16% phosphite, and which are dilutedapproximately 1:100 to about 1:300. The resulting pH of thesefertilizers varies significantly depending upon the pH of the waterused, thus affecting the availability of the nutrients for foliaruptake. In contrast, the highly concentrated fertilizers of the presentinvention, which can be diluted with water at a ratio of about 1:600,allow for more cost effective shipping, handling, and application. Theyresult in greater uptake of phosphorus by the canopy of plants thantraditional phosphate or recent phosphite fertilizers not formulated inthis manner.

The formulations provided herein also make it possible to formulatevarious combinations of other essential plant nutrients or otherinorganic or organic compounds as desired and maintain their solubilitywhen used over a wide range of concentrations and pHs, which is notpossible for present phosphate or phosphite fertilizers. For example,boron, manganese, calcium; iron and other elements can be provided atrelatively high concentrations in these formulations. Thus, thesephosphorus fertilizers also enhance the canopy uptake of other mineralnutrients essential to plants. They can be used as a canopy applicationto improve pre- and post-harvest crop quality.

Formulations can also prepared with copper. However, when highconcentrations of copper are used; the copper is not-fully solubilized.In this situation, the insoluble copper is desirable as it preventsrapid uptake of the copper and thus-minimizes the potential for coppertoxicity. As the insoluble copper is rewetted over night by dew,dissolution occurs so that additional copper is taken up. The bufferingcapacity of the formulation maintains the pH at a foliage-acceptable pHwhen the insoluble copper is rewetted so that conditions are optimal foruptake and are benign to the plant tissues. While copper is an elementessential to plants, it is required in only small amounts. In relationto nitrogen, plants require, in general, 10,000- to 75,000-fold lesscopper. Provided to the foliage of the plant at the rate provided bythis formulation, copper is a very effective fungicide, in addition tobeing a plant nutrient and fertilizer.

In addition to the above-mentioned advantages, the formulationsdisclosed have a direct benefit to the environment. Because theformulations allow successful foliar feeding of phosphorus to a numberof plants that do not effectively take up phosphorus when supplied inphosphate or polyphosphate forms, and because these formulations enhancethe uptake of other nutrients, they are cost-effective and can replaceless efficient, traditional soil-feeding methods. This results inreducing phosphate pollution of the groundwater and eutrophication offreshwater ponds, lakes and streams.

The phosphorus fertilizers disclosed herein can also be advantageouslyapplied through the soil or by irrigation systems as solid (granular) orliquid formulations. These formulations can be used at pHs sufficientlylow to clean irrigation lines and alter the pH of the soil to solvealkalinity problems while supplying essential nutrients to plants.Example 2, below discloses a suitable formulation for irrigationapplication. With irrigation application, the fertilizer flowing throughthe irrigation system will typically have a pH lower than about 2.5,usually less than about pH 1.5. The low pH is designed to supplyphosphorus while killing bacteria and algae (slime) which plugirrigation lines, thus cleaning the lines. The low pH also dissolvescalcium carbonate deposits at and around the emitters, and solubilizesthe calcium carbonate so Ca²⁺ is available to the plant. Once deliveredto the soil near the plant, sufficient water is applied to achieve a pHsuitable for phosphorus uptake by the plant. The form in which thephosphorus is supplied in these formulations is more mobile thanphosphate fertilizers or than the simple salts of phosphorous acidrecently being sold as fertilizers, and thus more available and morereadily taken up by the roots of plants. An advantage of theseformulations is that the form in which phosphorus is supplied does notinhibit the development of mycorrhizal fungi to the same degree thattraditional phosphate fertilizers do. The present compositions can alsobe formulated with certain nutrients in addition to phosphorus that arereadily absorbed through soil applications at pH of about 5.5 to about7.0. Such nutrients include nitrogen, calcium, magnesium, potassium,molybdenum, boron, and sulfur.

Another advantage with the phosphorus fertilizers disclosed herein isthat they do not support the growth of green algae to the same degreethat traditional phosphate fertilizers do. This is of significantimportance to agriculture, commercial nurseries, the ornamental and cutflower industry, and the home and garden industry, as it will preventthe growth of green algae which typically proliferate and plugirrigation emitters, foul pots and benches, and provide a niche for thegrowth of pathogenic bacteria and fungi. These formulations also endowthe phosphorus fertilizer with anti-viral, anti-bacterial andanti-fungal activity. This bacterialcidal activity in a phosphorusfertilizer makes it possible to use this fertilizer to inhibitice-nucleating bacteria to thus protect plants from frost damage.

Methods of Preparation

The phosphorus fertilizers are prepared by first forming solutions ofthe phosphorous and organic acids. Other desired nutrients can then beadded with constant stirring. The amount of phosphorous relative toorganic acid is not critical, as long as appropriate buffering andsolubility are achieved. Generally the amount of organic acid that isadded will depend upon the form in which the nutrient elements areadded. For example, if calcium is to be added in the form of calciumhydroxide (a base), then the acid form of the organic acid, for examplecitric acid, would be used rather than its salt, citrate. In addition tothe desired nutrients, other additives, that are known in the fertilizerindustry, can be added. These include, for example, wetting-agents,surfactants, spreaders, stickers etc., and are described in The FarmChemical Handbook, supra (incorporated herein by reference). Thefertilizer compositions can also be prepared as solid formulations,identical to the liquid ones by simply leaving out all of the water. Theproperties are the same as the liquid formulations but have theadditional advantage of weighing less for the same amount of nutrient.

Methods of Application

The fertilizer is applied according to crop-specific recommendationswhich will depend upon the application method (foliar, soil, irrigation,etc.), time of application, rate of application, and productformulation. Crops that will benefit from the fertilizer include, butare not limited to, avocado, citrus, mango, coffee, deciduous treecrops, grapes and other berry crops, soybean and other commercial beans,corn, tomato, cucurbits and cucumis species, lettuce, potato, sugarbeets, peppers, sugarcane, hops, tobacco, pineapple, coconut palm andother commercial and ornamental palms, hevea rubber, and ornamentalplants.

In addition to the foliar, soil, and irrigation application methodsmentioned above, the present fertilizer may prove beneficial to certaincrops through other application methods. For example, trunk paints orother methodologies may provide for a continuous low supply offertilizers, such as, for example, “intravenous” feeding as practiced inthe boron nutrition of soybeans.

In order that the invention described herein may be more fullyunderstood, the following examples are set forth. All chemicals usedwere of analytical reagent quality and approximately 100% by weightunless otherwise specified. All formulations are expressed in terms ofweight to volume. It should be understood that these examples are forillustrative purposes only and are not to be construed as limiting -thescope of--the invention in-any manner.

EXAMPLE 1

A formulation was prepared of 1 gallon of 0-40-0 fertilizer with 3.86lbs H₃PO₃, 1.34 lbs tripotassium citrate, 1.34 lbs of trisodium citrate,and 4.0 lbs of 58% ammonium hydroxide. The components were dissolved inwater with constant stirring. This single formulation can be used at arate of 2 quarts in as little as 20 gallons of water of pH 6.5 to 8.5 upto 300 gallons of water of pH 6.5 to 8.5 and maintain a pH between 5.5to 6.5 without the formation of any precipitate.

EXAMPLE 2

A formulation was prepared of 1 gallon of 0-40-0 fertilizer with 3.86lbs H₃PO₃ and 0.5 lbs citric acid. This formulation is stable at pH 1.0or less and is designed for application through the irrigation system.It is stable against oxidation and precipitation when supplied throughthe irrigation water.

EXAMPLE 3

A formulation was prepared of 1 gallon of 0-30-0 fertilizer with 74.89%elemental boron with 2.89 lbs H₃PO₃, 28.67 lbs borax (Na₂B₄O₇.10 H₂O),17.16 lbs boric acid (H₃BO₃), 1.54 lbs H₂SO₄ and 2.67 lbs citric acid. Asolution of the phosphorous and citric acid was first prepared, then theother elements were added with constant stirring. This formulation canbe used at the rate of 2 quarts in as little as 20 gallons of water ofpH between 6.5 to 8.5 up to 300 gallons of water of pH 6.5 to 8.5 andmaintain a pH between 5.5 to 6.5 without the formation of anyprecipitate.

EXAMPLE 4

A formulation was prepared of 1 gallon of 0-30-0 fertilizer with 21.57%Zn and 23.22% Mn with 2.89 lbs of H₃PO₃, 7.92 lbs ZnSO₄, 7.16 lbsMn(H₂PO₂)₂.H₂O, 0.61 lbs citric acid and 0.87 lbs 58% NH₄OH. Thisformulation can be used at the rate of two quarts in as little as 20gallons of water of pH between 6.5 to 8.5 up to 300 gallons of water ofpH between 6.5 to 8.5 and maintain a pH between 5.5 to 6.5 without theformation of any precipitate.

EXAMPLE 5

A formulation was prepared of 1 gallon of 0-30-0 fertilizer with 5.4%Ca. It was packaged in a two-container system where 1 gallon of solutionA contained 2.89 lbs H₃PO₃, 0.68 lbs Ca(OH)₂, and 0.28 lbs citric acid,and 1 gallon of solution B contained 0.16 lbs Ca(OH)₂, 0.60 lbs KOH,3.34 lbs 58% NH₄OH, 0.28 lbs citric acid, and 0.67 lbs EDTA(ethylenediaminetetraacetic acid). Two quarts of solution A can be addedto as little as 20 gallons of water of pH between 6.5 to 8.5 up to 300gallons of water of pH between 6.5 to 8.5 followed by the addition oftwo quarts of solution B. The final solution is between pH 5.5 to 6.5and without precipitation.

A formulation of 1 gallon of 0-30-0 fertilizer with 4.32% Ca can be madewithout requiring EDTA. This formulation is also packaged in atwo-container system where 1 gallon of solution A contains 2.89 lbsH₃PO₃, 0.67 lbs Ca(OH)₂ and 0.28 lbs of citric acid, while 1 gallon ofsolution B contains 2.67 lbs of 58% NH₄OH, 0.6 lbs KOH. Two quarts ofsolution A can be added to as little as 20 gallons of water of pHbetween 6.5 to 8.5 up to 300 gallons of water of pH between 6.5 and 8.5followed by the addition of two quarts of solution B. The final pH ofthe solution is between 5.5 and 6.5 and without precipitation.

EXAMPLE 6

A formulation was prepared of 1 gallon of 0-30-30 fertilizer with 2.89lbs H₃PO₃, 2.99 lbs KOH, and 0.84 lbs citric acid. Two quarts can beadded to as little as 20 gallons of water of pH between 6.5 to 8.5 andup to 300 gallons of water of pH between 6.5 and 8.5. The pH of thefinal solution is between 5.5 and 6.5 without precipitation.

EXAMPLE 7

A formulation was prepared of 1 gallon of 0-30-0 fertilizer having 4.8%iron with 2.89 H₃PO₃, 1.75 lbs iron-citrate, 0.74 lbs KOH, 0.62 lbsNaOH, and 2.00 lbs of 58% NH₄OH. Two quarts of the formulation can beadded to as little as 20 gallons of water pH 6.5 to 8.5 and up to 300gallons of water of pH 6.5 to 8.5. The pH of the final solution isbetween 5.5 to 6.7 without precipitation.

EXAMPLE 8

A formulation was prepared of 1 gallon of 0-30-0 fertilizer having23.22% manganese with 2.89 H₃PO₃, 7.16 lbs. Mn(H₂PO₂)₂, and 0.133 lbs.sodium citrate. Two quarts of the formulation can be added to as littleas 20 gallons of water pH 6.5 to 8.5 and up to 300 gallons of water ofpH 6.5 to 8.5. The pH of the final solution is between 5.5 to 6.5without precipitation.

EXAMPLE 9

A formulation was prepared of 1 gallon of 0-30-0 fertilizer having 57%copper with 2.89 H₃PO₃, 7.3 lbs Cu(OH)₂ (57% Cu), and 1.34 lbs of 58%NH₄OH. Two quarts can be added to as little as 20 gallons of water of pH6.5 to 8.5 up to 300 gallons of water of pH 6.5 to 8.5. The pH of thefinal solution is between 5.5 to 6.5. The copper is not fully soluble,however this is desirable in that it prevents the rapid uptake of copperwhen applied to plant foliage.

1-24. (canceled)
 25. A multiple buffered phosphorus fertilizercomprising: (i) a first buffer system comprising a phosphorous acid anda salt of a phosphorous acid; and (ii) a second buffer system comprisingan organic acid and a salt of an organic acid.
 26. The multiple bufferedphosphorus fertilizer according to claim 25, wherein phosphorus in saidmultiple buffered phosphorus fertilizer is present in an amountequivalent to about 0.30 kg/L or greater P₂O₅.
 27. The multiple bufferedphosphorus fertilizer according to claim 25, wherein said organic acidis a member selected from dicarboxylic acids, tricarboxylic acids andcombinations thereof.
 28. The multiple buffered phosphorus fertilizeraccording to claim 27, wherein said organic acid is citric acid.
 29. Themultiple buffered phosphorus fertilizer according to claim 25, whereinsaid phosphorous acid is a member selected from phosphorous acid,hypophosphorous acid, polyphosphorous acid, polyhypophosphorous acid andcombinations thereof.
 30. The multiple buffered phosphorus fertilizeraccording to claim 25, wherein said fertilizer has a pH of about 5.0 toabout 7.0.
 31. The multiple buffered phosphorus fertilizer according toclaim 30, wherein said fertilizer has a pH of about 5.5 to about 6.5.32. The multiple buffered phosphorus fertilizer according to claim 25,wherein the number of buffering systems is two.
 33. A substantiallyfully solubilized use-dilution fertilizer having a pH acceptable forfoliage uptake of phosphorus, said use-dilution fertilizer comprising:(i) the multiple buffered phosphorus fertilizer according to claim 25;and (ii) water.
 34. The use-dilution fertilizer according to claim 33,wherein said use-dilution fertilizer comprises a ratio of said multiplebuffered phosphorus fertilizer to said water of about 1:40 to about1:600.
 35. The use-dilution fertilizer according to claim 33, whereinsaid water has a pH of about 6.5 to about 8.5.
 36. The multiple bufferedphosphorus fertilizer according to claim 25, wherein said multiplebuffered phosphorus fertilizer is essentially clear and devoid ofprecipitate.
 37. The multiple buffered phosphorus fertilizer accordingto claim 25, further comprising a plant nutrient, wherein said plantnutrient is a member selected from nitrogen, potassium, sulfur, calcium,magnesium, boron, iron, manganese, molybdenum, zinc, ammonia andcombinations thereof.
 38. The multiple buffered phosphorus fertilizeraccording to claim 25, wherein said multiple buffered phosphorusfertilizer is in a liquid form.
 39. The multiple buffered phosphorusfertilizer according to claim 25, wherein said multiple bufferedphosphorus fertilizer is in a solid form.
 40. The multiple bufferedphosphorus fertilizer of claim 25, wherein phosphorus in said multiplebuffered phosphorus fertilizer is present in an amount equivalent tofrom about 0.30 kg/L to about 0.40 kg/L P₂O₅.
 41. The multiple bufferedphosphorus fertilizer according to claim 40, wherein said organic acidis a member selected from dicarboxylic acids, tricarboxylic acids andcombinations thereof.
 42. The multiple buffered phosphorus fertilizeraccording to claim 41, wherein said organic acid is citric acid.
 43. Themultiple buffered phosphorus fertilizer according to claim 40, whereinsaid phosphorous acid is a member selected from phosphorous acid,hypophosphorous acid, polyphosphorous acid, polyhypophosphorous acid andcombinations thereof.
 44. The multiple buffered phosphorus fertilizeraccording to claim 40, wherein said fertilizer has a pH of about 5.0 toabout 7.0.
 45. The multiple buffered phosphorus fertilizer according toclaim 44, wherein said fertilizer has a pH of about 5.5 to about 6.5.46. The multiple buffered phosphorus fertilizer according to claim 40,wherein the number of buffering systems is two.
 47. A substantiallyfully solubilized use-dilution fertilizer having a pH acceptable forfoliage uptake of phosphorus, said use-dilution fertilizer comprising:(i) the multiple buffered phosphorus fertilizer according to claim 40;and (ii) water.
 48. The use-dilution fertilizer according to claim 47,wherein said use-dilution fertilizer comprises a ratio of said multiplebuffered phosphorus fertilizer to said water of about 1:40 to about1:600.
 49. The use-dilution fertilizer according to claim 47, whereinsaid water has a pH of about 6.5 to about 8.5.
 50. The multiple bufferedphosphorus fertilizer according to claim 40, wherein said multiplebuffered phosphorus fertilizer is essentially clear and devoid ofprecipitate.
 51. The multiple buffered phosphorus fertilizer accordingto claim 40, further comprising a plant nutrient, wherein said plantnutrient is a member selected from nitrogen, potassium, sulfur, calcium,magnesium, boron, iron, manganese, molybdenum, zinc, ammonia andcombinations thereof.
 52. The multiple buffered phosphorus fertilizeraccording to claim 40, wherein said multiple buffered phosphorusfertilizer is in a liquid form.
 53. The multiple buffered phosphorusfertilizer according to claim 40, wherein said multiple bufferedphosphorus fertilizer is in a solid form.
 54. The multiple bufferedphosphorus fertilizer of claim 25, wherein phosphorus in said multiplebuffered phosphorus fertilizer is present in an amount equivalent tofrom about 0.30 kg/L to about 0.46 kg/L P₂O₅.
 55. The multiple bufferedphosphorus fertilizer according to claim 54, wherein said organic acidis a member selected from dicarboxylic acids, tricarboxylic acids andcombinations thereof.
 56. The multiple buffered phosphorus fertilizeraccording to claim 55, wherein said organic acid is citric acid.
 57. Themultiple buffered phosphorus fertilizer according to claim 54, whereinsaid phosphorous acid is a member selected from phosphorous acid,hypophosphorous acid, polyphosphorous acid, polyhypophosphorous acid andcombinations thereof.
 58. The multiple buffered phosphorus fertilizeraccording to claim 54, wherein said multiple buffered phosphorusfertilizer has a pH of about 5.0 to about 7.0.
 59. The multiple bufferedphosphorus fertilizer according to claim 58, wherein said multiplebuffered phosphorus fertilizer has a pH of about 5.5 to about 6.5. 60.The multiple buffered phosphorus fertilizer according to claim 54,wherein the number of buffering systems is two.
 61. A substantiallyfully solubilized use-dilution fertilizer having a pH acceptable forfoliage uptake of phosphorus, said use-dilution fertilizer comprising:(i) the multiple buffered phosphorus fertilizer according to claim 54;and (ii) water.
 62. The use-dilution fertilizer according to claim 61,wherein said use-dilution fertilizer comprises a ratio of said multiplebuffered phosphorus fertilizer to said water of about 1:40 to about1:600.
 63. The use-dilution fertilizer according to claim 61, whereinsaid water has a pH of about 6.5 to about 8.5.
 64. The multiple bufferedphosphorus fertilizer according to claim 54, wherein said multiplebuffered phosphorus fertilizer is essentially clear and devoid ofprecipitate.
 65. The multiple buffered phosphorus fertilizer accordingto claim 54, further comprising a plant nutrient, wherein said plantnutrient is a member selected from nitrogen, potassium, sulfur, calcium,magnesium, boron, iron, manganese, molybdenum, zinc, ammonia andcombinations thereof.
 66. The multiple buffered phosphorus fertilizeraccording to claim 54, wherein said multiple buffered phosphorusfertilizer is in a liquid form.
 67. The multiple buffered phosphorusfertilizer according to claim 54, wherein said multiple bufferedphosphorus fertilizer is in a solid form.
 68. A multiple bufferedphosphite fertilizer comprising: (i) a first buffer system comprising aphosphite; and (ii) a second buffer system comprising an organic acidand a salt of an organic acid.
 69. The multiple buffered phosphitefertilizer according to claim 68, wherein phosphorus in said multiplebuffered phosphite fertilizer is present in an amount equivalent toabout 0.30 kg/L or greater P₂O₅.
 70. The multiple buffered phosphitefertilizer according to claim 68, wherein said organic acid is a memberselected from dicarboxylic acids, tricarboxylic acids and combinationsthereof.
 71. The multiple buffered phosphite fertilizer according toclaim 70, wherein said organic acid is citric acid.
 72. The multiplebuffered phosphite fertilizer according to claim 68, wherein saidphosphite is a salt of a phosphorous acid, wherein said phosphorous acidis a member selected from phosphorous acid, hypophosphorous acid,polyphosphorous acid, polyhypophosphorous acid and combinations thereof.73. The multiple buffered phosphite fertilizer according to claim 68,wherein said multiple buffered phosphite fertilizer has a pH of about5.0 to about 7.0.
 74. The multiple buffered phosphite fertilizeraccording to claim 73, wherein said multiple buffered phosphitefertilizer has a pH of about 5.5 to about 6.5.
 75. The multiple bufferedphosphite fertilizer according to claim 68, wherein the number ofbuffering systems is two.
 76. A substantially fully solubilizeduse-dilution fertilizer having a pH acceptable for foliage uptake ofphosphorus, said use-dilution fertilizer comprising: (i) the multiplebuffered phosphite fertilizer according to claim 68; and (ii) water. 77.The use-dilution fertilizer according to claim 76, wherein saiduse-dilution fertilizer comprises a ratio of said multiple bufferedphosphite fertilizer to said water of about 1:40 to about 1:600.
 78. Theuse-dilution fertilizer according to claim 76, wherein said water has apH of about 6.5 to about 8.5.
 79. The multiple buffered phosphitefertilizer according to claim 68, wherein said multiple bufferedphosphite fertilizer is essentially clear and devoid of precipitate. 80.The multiple buffered phosphite fertilizer according to claim 68,further comprising a plant nutrient, wherein said plant nutrient is amember selected from nitrogen, potassium, sulfur, calcium, magnesium,boron, iron, manganese, molybdenum, zinc, ammonia and combinationsthereof.
 81. The multiple buffered phosphite fertilizer according toclaim 68, wherein said multiple buffered phosphite fertilizer is in aliquid form.
 82. The multiple buffered phosphite fertilizer according toclaim 68, wherein said multiple buffered phosphite fertilizer is in asolid form.
 83. The multiple buffered phosphite fertilizer of claim 68,wherein phosphorus in said multiple buffered phosphite fertilizer ispresent in an amount equivalent to from about 0.30 kg/L to about 0.40kg/L P₂O₅.
 84. The multiple buffered phosphite fertilizer according toclaim 83, wherein said organic acid is a member selected fromdicarboxylic acids, tricarboxylic acids and combinations thereof. 85.The multiple buffered phosphite fertilizer according to claim 84,wherein said organic acid is citric acid.
 86. The multiple bufferedphosphite fertilizer according to claim 83, wherein said phosphite is asalt of a phosphorous acid, wherein said phosphorous acid is a memberselected from phosphorous acid, hypophosphorous acid, polyphosphorousacid, polyhypophosphorous acid and combinations thereof.
 87. Themultiple buffered phosphite fertilizer according to claim 83, whereinsaid multiple buffered phosphite fertilizer has a pH of about 5.0 toabout 7.0.
 88. The multiple buffered phosphite fertilizer according toclaim 87, wherein said multiple buffered phosphite fertilizer has a pHof about 5.5 to about 6.5.
 89. The multiple buffered phosphitefertilizer according to claim 83, wherein the number of bufferingsystems is two.
 90. A substantially fully solubilized use-dilutionfertilizer having a pH acceptable for foliage uptake of phosphorus, saiduse-dilution fertilizer comprising: (i) the multiple buffered phosphitefertilizer according to claim 83; and (ii) water.
 91. The use-dilutionfertilizer according to claim 90, wherein said use-dilution fertilizercomprises a ratio of said multiple buffered phosphite fertilizer to saidwater of about 1:40 to about 1:600.
 92. The use-dilution fertilizeraccording to claim 90, wherein said water has a pH of about 6.5 to about8.5.
 93. The multiple buffered phosphite fertilizer according to claim83, wherein said multiple buffered phosphite fertilizer is essentiallyclear and devoid of precipitate.
 94. The multiple buffered phosphitefertilizer according to claim 83, further comprising a plant nutrient,wherein said plant nutrient is a member selected from nitrogen,potassium, sulfur, calcium, magnesium, boron, iron, manganese,molybdenum, zinc, ammonia and combinations thereof.
 95. The multiplebuffered phosphite fertilizer according to claim 83, wherein saidmultiple buffered phosphite fertilizer is in a liquid form.
 96. Themultiple buffered phosphite fertilizer according to claim 83, whereinsaid multiple buffered phosphite fertilizer is in a solid form.
 97. Themultiple buffered phosphite fertilizer of claim 68, wherein phosphorusin said multiple buffered phosphite fertilizer is present in an amountequivalent to from about 0.30 kg/L to about 0.46 kg/L P₂O₅.
 98. Themultiple buffered phosphite fertilizer according to claim 97, whereinsaid organic acid is a member selected from dicarboxylic acids,tricarboxylic acids and combinations thereof.
 99. The multiple bufferedphosphite fertilizer according to claim 98, wherein said organic acid iscitric acid.
 100. The multiple buffered phosphite fertilizer accordingto claim 97, wherein said phosphite is a salt of a phosphorous acid,wherein said phosphorous acid is a member selected from phosphorousacid, hypophosphorous acid, polyphosphorous acid, polyhypophosphorousacid and combinations thereof.
 101. The multiple buffered phosphitefertilizer according to claim 97, wherein said multiple bufferedphosphite fertilizer has a pH of about 5.0 to about 7.0.
 102. Themultiple buffered phosphite fertilizer according to claim 101, whereinsaid multiple buffered phosphite fertilizer has a pH of about 5.5 toabout 6.5.
 103. The multiple buffered phosphite fertilizer according toclaim 97, wherein the number of buffering systems is two.
 104. Asubstantially fully solubilized use-dilution fertilizer having a pHacceptable for foliage uptake of phosphorus, said use-dilutionfertilizer comprising: (i) the multiple buffered phosphite fertilizeraccording to claim 97; and (ii) water.
 105. The use-dilution fertilizeraccording to claim 104, wherein said use-dilution fertilizer comprises aratio of said multiple buffered phosphite fertilizer to said water ofabout 1:40 to about 1:600.
 106. The use-dilution fertilizer according toclaim 104, wherein said water has a pH of about 6.5 to about 8.5. 107.The multiple buffered phosphite fertilizer according to claim 97,wherein said multiple buffered phosphite fertilizer is essentially clearand devoid of precipitate.
 108. The multiple buffered phosphitefertilizer according to claim 97, further comprising a plant nutrient,wherein said plant nutrient is a member selected from nitrogen,potassium, sulfur, calcium, magnesium, boron, iron, manganese,molybdenum, zinc, ammonia and combinations thereof.
 109. The multiplebuffered phosphite fertilizer according to claim 97, wherein saidmultiple buffered phosphite fertilizer is in a liquid form.
 110. Themultiple buffered phosphite fertilizer according to claim 97, whereinsaid multiple buffered phosphite fertilizer is in a solid form.
 111. Asubstantially fully solubilized use-dilution fertilizer comprising aconcentrate comprising a first buffer system, wherein said first buffersystem is derived from a phosphorous acid and salt of a phosphorousacid, wherein phosphorus is present in said first buffer system in anamount equivalent to at least about 0.30 kg/L P₂O₅, such that when saidconcentrate is diluted with water having a pH as low as about 6.5 at aratio as high as about 1 part concentrate to about 40 parts water, thereis formed a substantially fully solubilized use-dilution fertilizerhaving a foliage acceptable pH for phosphorus uptake.
 112. Theuse-dilution fertilizer of claim 111, wherein said phosphorus is presentin said first buffer system in an amount equivalent to between about0.30 kg/L P₂O₅ and about 0.40 kg/L P₂O₅.
 113. The use-dilutionfertilizer of claim 111, wherein said substantially fully solubilizeduse-dilution fertilizer further comprises a second buffer systemcomprising an organic acid and a salt of an organic acid.
 114. Theuse-dilution fertilizer of claim 113, wherein said first buffer systemcontains phosphorus in an amount equivalent to between about 0.30 kg/LP₂O₅ and about 0.40 kg/L P₂O₅.
 115. A method of making a substantiallyfully solubilized use-dilution fertilizer, said method comprising:mixing water with a pH as low as about 6.5 and a concentrate comprisinga first buffer system comprising a phosphorous acid and a salt of aphosphorous acid, thus forming said use-dilution fertilizer, whereinsaid use-dilution fertilizer has phosphorus in an amount equivalent toat least about 0.30 kg/L P₂O₅, has a ratio of concentrate to water of ashigh as about 1 part concentrate to about 40 parts water, and has afoliage acceptable pH for phosphorus uptake.
 116. The method of claim115, further comprising adding a plant nutrient to said use-dilutionfertilizer.
 117. The method of claim 116, wherein said plant nutrient isa member selected from nitrogen, calcium, magnesium, potassium,molybdenum, boron, and sulfur.
 118. The method of claim 116, whereinsaid plant nutrient is potassium.
 119. The method of claim 115, whereinsaid mixing further comprises a second buffer system comprising anorganic acid and a salt of an organic acid.
 120. A method of applyingphosphorus to a plant, said method comprising: (a) mixing water with apH as low as about 6.5 and a concentrate comprising a first buffersystem comprising a phosphorous acid and a salt of a phosphorous acid,thus forming a substantially fully solubilized use-dilution fertilizer,wherein said use-dilution fertilizer has phosphorus in an amountequivalent to at least about 0.30 kg/L P₂O₅, has a ratio of concentrateto water of as high as about 1 part concentrate to about 40 parts water,and has a foliage acceptable pH for phosphorus uptake; and (b) applyingsaid substantially fully solubilized use-dilution fertilizer to thefoliage of said plant, thus applying said phosphorus to said plant. 121.The method of claim 120, further comprising adding a plant nutrient tosaid use-dilution fertilizer.
 122. The method of claim 121, wherein saidplant nutrient is a member selected from nitrogen, calcium, magnesium,potassium, molybdenum, boron, and sulfur.
 123. The method of claim 121,wherein said plant nutrient is potassium.
 124. The method of claim 120,wherein said mixing further comprises a second buffer system comprisingan organic acid and a salt of an organic acid.
 125. A substantiallyfully solubilized use-dilution fertilizer having a foliage acceptable pHfor phosphorus uptake, produced by a process comprising: mixing waterwith a pH as low as about 6.5 and a concentrate comprising a firstbuffer system consisting of a phosphorous-containing acid and saltthereof, thus forming said use-dilution fertilizer, wherein saiduse-dilution fertilizer has phosphorus in an amount equivalent to atleast about 0.30 kg/L P₂O₅, and has a ratio of concentrate to water ofas high as about 1 part concentrate to about 40 parts water, and has afoliage acceptable pH for phosphorus uptake.
 126. The use-dilutionfertilizer of claim 125, further comprising adding a plant nutrient tosaid use-dilution fertilizer.
 127. The use-dilution fertilizer of claim126, wherein said plant nutrient is a member selected from nitrogen,calcium, magnesium, potassium, molybdenum, boron, and sulfur.
 128. Theuse-dilution fertilizer of claim 126, wherein said plant nutrient ispotassium.
 129. The use-dilution fertilizer of claim 125, wherein saidmixing further comprises a second buffer system comprising an organicacid and a salt of an organic acid.
 130. A substantially fullysolubilized use-dilution fertilizer having a foliage acceptable pH forphosphorus uptake, produced by a process comprising: mixing water with apH as low as about 6.5 and a concentrate comprising a first buffersystem comprising phosphite, thus forming said use-dilution fertilizer,wherein said use-dilution fertilizer has phosphorus in an amountequivalent to at least about 0.30 kg/L P₂O₅, has a ratio of concentrateto water of as high as about 1 part concentrate to about 40 parts water,and has a foliage acceptable pH for phosphorus uptake.
 131. Theuse-dilution fertilizer of claim 130, further comprising adding a plantnutrient to said use-dilution fertilizer.
 132. The use-dilutionfertilizer of claim 131, wherein said plant nutrient is a memberselected from nitrogen, calcium, magnesium, potassium, molybdenum,boron, and sulfur.
 133. The use-dilution fertilizer of claim 131,wherein said plant nutrient is potassium.
 134. The use-dilutionfertilizer of claim 130, wherein said mixing further comprises a secondbuffer system comprising an organic acid and a salt of an organic acid.